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AD7724:  Dual, 7th-Order, Sigma-Delta Modulator

Product Details

The AD7724 is a dual 7th-order, sigma-delta modulator - it's dual version of the AD7720. Its SNR performance is 90 dB over a 90 kHz bandwidth. The part operates from a 5 V supply and accepts a differential input range of 0 V to 2.5 V or ±1.25 V centered about a common-mode bias. The analog inputs are continuously sampled by the analog modulators, eliminating the need for external sample and hold circuitry. The input information is contained in the output stream as a density of ones. The original information can be reconstructed with an appropriate digital filter.

The part provides an accurate on-chip 2.5 V reference. A reference input/output function is provided to allow either the internal reference or an external system reference to be used as the reference source for the part.

The part is offered in a 48-pin TQFP package and is designed to operate from –40°C to 85°C.

Typically, the AD7724 is followed by a digital filter to achieve a parallel A/D result, which is just like our standard sigma-delta A/Ds. Having a separate filter allows users to customize their filter respose, which can be done with one of our own DSPs or with a gate array.


  • 13 MHz Master Clock Frequency
  • 0 V to +2.5 V or ±1.25 V Input Range
  • Single Bit Output Stream
  • 90 dB Dynamic Range
  • Logic Outputs 3 V/5 V Compatible
  • Power Supplies
    - AVDD, DVDD: 5 V ± 5%
    - DVDD1: 3 V ± 5%
  • On-Chip 2.5 V Voltage Reference
  • 48-Lead LQFP

Functional Block Diagram for AD7724


Title Content Type File Type
AD7724: Dual CMOS Sigma-Delta Modulators Data Sheet (Rev B, 03/2002) (pdf, 288 kB) Data Sheets PDF
AN-311: How to Reliably Protect CMOS Circuits Against Power Supply Overvoltaging  (pdf, 217 kB) Application Notes PDF
AN-397: Electrically Induced Damage to Standard Linear Integrated Circuits:  (pdf, 149 kB)
The Most Common Causes and the Associated Fixes to Prevent Reoccurrence
Application Notes PDF
AN-202: An IC Amplifier User’s Guide to Decoupling, Grounding, and Making Things Go Right for a Change  (pdf, 76 kB) Application Notes PDF
AN-389: Using Sigma-Delta Converters-Part 2  (pdf, 590 kB)
When to Use/How to Use Sigma-Delta ADCs; Continuation of Part 1 Discussion.
Application Notes PDF
AN-388: Using Sigma-Delta Converters-Part 1  (pdf, 590 kB)
When to Use/How to Use Sigma-Delta ADCs
Application Notes PDF
AN-283: Sigma-Delta ADCs and DACs  (pdf, 1699 kB)
Overview of Sigma-Delta Concepts: Oversampling, Noise Shaping Using the Sigma-Delta Modulator, Digital Filtering and Decimation.
Application Notes PDF
MS-2210: Designing Power Supplies for High Speed ADC  (pdf, 327 kB) Technical Articles PDF
Delta-Sigma Rocks RF, As ADC Designers Jump On Jitter
(Electronic Design, 1/12/06)
Technical Articles HTML
Circuit Suggestions Using Features and Functionality of New Sigma-Delta ADCs Technical Articles HTML
Designing and Applying Remote Field Instruments
by Albert O' Grady and Jim Ryan, Analog Devices B.V.
...Good things can come in small packages because of on-chip capabilities
(Control Engineering, September 1998)
Technical Articles HTML
Ask the Applications Engineer-27: What problems am I most likely to run into when instrumenting an industrial system?
(Analog Dialogue, Vol. 33, No. 2, February, 1999)
Analog Dialogue HTML
RAQs index Rarely Asked Questions HTML
Glossary of EE Terms Glossary HTML

Design Tools,Models,Drivers & Software

Title Content Type File Type
Sigma-Delta ADC Tutorial
An interactive illustration showing the behavior of an idealized sigma-delta A/D converter.
Utilities and Conversions HTML

Evaluation Kits & Symbols & Footprints

Symbols and Footprints— Analog Devices offers Symbols & Footprints which are compatible with a large set of today’s CAD systems for broader and easier support.

SampleSample & Buy

Price, packaging, availability

AD7724 Model Options
Model Package Pins Temp.
Price*(100-499) Price*1000 pcs RoHS View PCN/ PDN Check Inventory/
AD7724ASTZ Status: Production 48 ld LQFP 48 Ind Tray, 250 $11.90 $10.12 Y  Material Info PCN Purchase
AD7724ASTZ-REEL Status: Production 48 ld LQFP 48 Ind Reel, 2000 - $10.12 Y  Material Info PCN Purchase
Price Table Help

The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.

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